I use 1/3 semolina and 2/3 regular all purpose flour
then follow the rest of the recipe it's great
it also freezes excellent

I've tried to buy 00 flour from Sainsburys and Tescos. Must have been out of luck!

Plain flour works

Sainsbury's do in fact sell a oo flour in a pink bag called pasta flour so it may even have some semolina flour it it.. The 00 flour makes an enormous difference. With it the dough I'd slinky and perfectly elastic, does not break up and behaves beautifully especially when hand making pizza (no eggs) or pasta.

A few pointers.
the correct way to measure egg/flour ratio is to add whole eggs to a well in the flour, no water not oil, until wet enough.. more flour or an egg as required.

Try not to roll a pizza, just stretch and prod gently by fingertips.

My best pizza recipe is 500g tipo oo, 10g best flake salt, preferably Isle de Re fleur de sel. Mix in 325g warm water but leave to soak half an hour. Only 3g yeast, mix till elastic, five mins, then make into six balls to leave covered in the fridge for even a week to use as required

I see you are north of the border so not sure if they have Sainsburys,

I was there the other day and they have an excellent range of foodie flours including the lesser spotted '00'.

Sainsbury oo is a quid per kilo. Tesco strong is from 40p to 20p on 3 for2. Strong flour matures if you like more flavour, can be prepared and kept in the fridge for days to meet Utalian standards of at least 4hrs proving. Sainsburys has enough gluten for this process too with the distinct advantage of becoming silky smooth and elastic, other pastry 00 do not retain elasticity so must be used immediately with bland results which is why Jamie adds semolina, however if you work the tesco strong flour till rubbery then prove before balling and storing covered it stretches just fine with more flavour, perhaps less crunch than Sainsburys but for third the price